Three Palestinians and an Israeli soldier were killed in fierce clashes in the Gaza Strip today.
The Israeli army said its forces were operating in Khan Younis and Beit Hanoun, towns in south and north Gaza from where Palestinian militants often launch rockets into Israel.
But the army had no immediate word on any Israeli casualties in Gaza.
Hamas said its fighters fired an anti-tank rocket at Israeli soldiers near Beit Hanoun, killing one and wounding at least one more. Another Israeli soldier was killed in Gaza two weeks ago.
Israeli tanks and helicopters fired on Beit Hanoun, killing a Palestinian gunman and a civilian, Hamas and hospital officials said.
At least 12 other Palestinians were wounded.
Asked about Beit Hanoun, the Israeli army confirmed that its forces were fighting Palestinian gunmen there but did not elaborate.
Hamas said one of its gunmen was killed in a clash with Israeli troops in Khan Younis. The Israeli army said forces in the town shot two gunmen but had no word on their condition.
Israel quit Gaza in 2005 after 38 years of occupation but has regularly staged commando raids and air strikes against suspected militant bases and rocket crews.
Hamas, an Islamist group that seized control of Gaza in a June civil war with secular rivals, has deployed squads of gunmen in frontier areas in hope of ambushing Israeli forces.
"We reaffirm that the enemy will never pass through our areas, except over the dead bodies of their soldiers," Hamas's armed wing said in a statement.
In the Israeli-occupied West Bank, an Israeli soldier was wounded when his patrol was attacked by Palestinian gunmen, the army said. The Popular Front for the Liberation of Palestine, a small leftist radical group, claimed responsibility for the ambush. Troops detained three Nablus residents on suspicion of militant ties.